DESCRIPTION: (adapted verbatim from the investigator's abstract) Prostatic adenocarcinoma is the most common cancer diagnosed in males, yet currently available methods for early detection of prostate cancer are inadequate and limited in accuracy. The overall goal of this project is to identify molecular abnormalities in prostate tumors to develop new tools for early diagnosis and evaluating prognosis of patients with prostate cancer. This will be accomplished by monitoring differences in gene expression in various types of prostatic tissues. Differentially expressed candidate genes may not be directly associated with tumorigenesis but may be useful for developing diagnostic markers. We will use differential display, reverse transcriptase PCR and gene discovery array filter screening to compare mRNA abundance in 5 human prostate tumor cell lines. Expression patterns of identifiable cDNA fragments will be confirmed by RNA blot analysis of cell lines. Positive candidates will be cloned, sequenced and identified by BLAST analysis. Next, identified cDNAs will be evaluated for their potential as tumor markers in prostate tissues. Prospective markers will be used to screen tissue samples from patients with prostate cancer. Paraffi- embedded archival or fresh samples will be screened by in situ hybridization. Fresh tissues will be screened by RTPCR. Five groups of tissue including uninvolved, nodular hyperplasia, different grades of PIN and prostatic adenocarcinoma will be screened, and results evaluated by statistical analysis. One or two of the most prominent candidate cDNA fragments will be pursued to develop an optimized diagnostic test. Either a full length or partial cDNA of a potential marker gene with known identity will be cloned by RTPCR. cDNA of genes with unknown identity will be cloned by rapid amplification of cDNA or by screening a cDNA library. Cloned cDNAs will be expressed in E. coli and more common proteins will be used to raise polyclonal antibodies. If indeed synthetic peptides may be used to raise antibody, depending upon the expression pattern, either an ELISA based assay using a polyclonal antibody or a more sensitive RTPCR based assay will be developed.